The transmission of data and energy in motor vehicles is typically performed via electrical lines and electrical contacts in the form of plugs. This also applies for signal and energy transmission between a control unit positioned in the vehicle body and electrical devices on and in the vehicle seats, restraint means, such as side airbags and seatbelt tighteners, in particular. Many of today's motor vehicles, such as minivans, offer the possibility of varying the number and arrangement of the available seats as needed by installing, removing, and reconfiguring individual seats or seat banks. In this context, contacting of the electrical devices on or in the vehicle seats via electrical cables and plug contacts has been shown to be problematic. Thus, the production and/or disconnection of the electrical connection represents an additional work step during installation, removal, and reconfiguration of the seats, which is in fact not absolutely necessary for the actual mounting of the seats, but cannot be forgotten in any case, since faulty triggering of the restraint means may have fatal consequences for the occupants. In addition, the guaranteed average service life of plugs which are currently used in connection with restraint systems is merely approximately 50 to 100 plugging and unplugging cycles. In addition, contamination of the plug contacts is to be always expected in the field of motor vehicles, so that in particular in the event of more frequent changes of the seating configuration, impairments of the electrical connection may occur.
A device for wireless transmission of signals and/or energy is described in German patent application No. 197 40 732. The transmission module on or in the vehicle body is connected via a line connection to a monitoring unit of the vehicle and is integrated into the floor or a side panel of the vehicle. The transmission module in the seat is also connected via a line connection to an electrical device of the vehicle seat, such as a seatbelt tightener. Both transmission modules include high-frequency coil antennas which are positioned diametrically opposing one another at a defined distance D when the vehicle seat is locked in properly. In the exemplary embodiment described in German Patent Application No. 197 40 732, the vehicle seat is removable from the vehicle together with its slide rail. The high-frequency coil antenna for the seat is mounted on the slide rail. During installation of the vehicle seat, the slide rail is attached to a defined point of the vehicle floor, so that the high-frequency coil antenna on or in the seat also assumes a defined position in relation to the vehicle floor and the high-frequency coil antenna positioned on or in the vehicle body.
The device described in German Patent Application No. 197 40 732 does overcome some of the problems initially described, which arise in connection with signal and energy transmission via electrical lines and plug contacts. However, it is nonetheless shown to be problematic in the event of more frequent changes of the seating configuration, since, due to their exposed arrangement on the vehicle body and the slide rail, the two high-frequency coil antennas are susceptible to mechanical impairments which are unavoidable during seat mounting. In this way, an undefined change in distance D between the two high-frequency coil antennas may occur, which may in turn lead to impairment of the signal and energy transmission between the two transmission modules.